ERROR：Only one ConfirmCallback is supported by each RabbitTemplate] with root cause —— RabbitMQ

错误：

　　Only one ConfirmCallback is supported by each RabbitTemplate] with root cause

原因：
　　因为Spring的Bean默认都是单例；而RabbitTemplate对象同样支持一个回调。

解决：使用@Scope("prototype")可通知Spring将被注解的Bean变为多例。

　　代码：

    // 改RabbitTemplate为多例
    @Bean
    @Scope(value = ConfigurableBeanFactory.SCOPE_PROTOTYPE)
    public RabbitTemplate rabbitTemplate(ConnectionFactory connectionFactory) {
        RabbitTemplate template = new RabbitTemplate(connectionFactory);
        template.setMandatory(true);
        template.setMessageConverter(new SerializerMessageConverter());
        return template;
    }

或：

    @Bean
    @Scope(value = ConfigurableBeanFactory.SCOPE_PROTOTYPE)
    public RabbitTemplate.ConfirmCallback confirmCallback(){
        RabbitTemplate.ConfirmCallback confirmCallback = new RabbitTemplate.ConfirmCallback() {
            @Override
            public void confirm(CorrelationData correlationData, boolean ack, String cause) {
                System.out.println("----------进入了confirmCallback方法---------");
                System.out.println("回调id：" + correlationData);
                System.out.println("确认情况：" + ack);
                System.out.println("原因：" + cause);
                if(ack){
                    System.out.println("消息发送成功");
                }else{
                    System.out.println("消息未进入交换机,保存到数据库，定时任务重发");
                }
            }
        };
        return confirmCallback;
    }
    @Bean
    @Scope(value = ConfigurableBeanFactory.SCOPE_PROTOTYPE)
    public RabbitTemplate.ReturnsCallback returnsCallback(){
        RabbitTemplate.ReturnsCallback returnsCallback = new RabbitTemplate.ReturnsCallback(){
            @Override
            public void returnedMessage(ReturnedMessage returned) {
                System.out.println("----------进入了returnsCallback方法---------");
                int code = returned.getReplyCode();
                System.out.println("相应码==>"+code);
                String replyText = returned.getReplyText();
                System.out.println("响应原因==>"+replyText);
                System.out.println("returned==>"+returned);
            }
        };

        return returnsCallback;
    }

    @Bean
    @Scope(value = ConfigurableBeanFactory.SCOPE_PROTOTYPE)
    public RabbitTemplate rabbitTemplate(ConnectionFactory connectionFactory) {
        RabbitTemplate template = new RabbitTemplate(connectionFactory);
        template.setMandatory(true);
//        template.setConfirmCallback(confirmCallback());
//        template.setReturnsCallback(returnsCallback());
        return template;
    }